Checkerwork for furnaces



Patented Mar. 3 0, 1948 UNITED STATES PATET oFFlcE cnEcxEaWoRx Foa FURNAcEs James E. MacDonald, Latrobe, Pa. Application November 20, 1944, SerialfNo. 564,261

3 Claims.

l My invention relates to checker brick structures here shown as employed in a blast furnace stove, but which can also be employed in connecttion with other types 'of furnaces.

O-ne object of my invention is to provide a checker structure wherein the bricks are of such shape that they can conveniently and accurately be laid to form checkerl flues and which provide lateral relief or flow passages between the various vertical fiues, without materially detracting from the strength of the checkerwork as a whole, and wherein there will not only be equalization of iioW pressures in the Various flues but if clogging occurs in any flue, only a small portion of the flue will be rendered ineffective, because of the lateral relief passages between flues.

Another advantage incident to my invention is the provision of more extended heating surface area for a given size of bricks, as compared toA bricks of' conventional forms.

Another object of my invention is to provide a structure of the character referred to, wherein lateral relief passageways have the upper and lower portions of their walls so sloped as to reduce resistance to the gas flow and current eddies, and wherein there is little danger of the passageways becoming clogged.

A further object of my invention is to provide a checkerwork structure of such form that bricks extending in one horizontal direction can conveniently be vertically stepped or offset with re' spect to adjacent bricks that extend laterally or -crosswise of said direction, without detracting view on an enlarged scale, through a portion of the checkerwork of Fig. 1; Fig. 3 is a perspective view of one of the bricks of Fig. 2; Fig. 4 is an enlarged elevational `View of a portion of the structure of Fig. 1; Fig. 5 is a perspective view showing a modification of the bricks of Figs. 1 to 3, and Fig. 6 shows still another modification.

Referring rst to Figs. 1.to 4, it will be understood that the stovewill be operated in a manmer common in this art, namely the heated and cold air or gas will be circulated through the stove alternately, in opposite directions, for delsired periods of time. The checkerwork l is supported on arches 8 and' rider bars 9-which may be in its vertical edges:

of any suitable well known form. Each brick III is formed substantially as shown in Fig. 3 and each is provided with vertical ribs II and horizontally-extending depressions or recesses I2 The bricks are preferably all of the same size, except for certain bricks in the top and bottom courses, as Will be hereinafter explained. One series of bricks I3 ex tend horizontally in one direction and the other series of bricks I4 extend crosswise relative to said direction. The bricks I3 are arranged in superposed relation with respect to one another, the ribs II` of each brick have endwise engagement with the ribs of vertically-adjacent bricks so that the ribs II not only serve to assist in sioned by recesses I2. All superposed bricks have engagement with one another on their horizontal surfaces throughout their entire length, which makes for greater stability of the structure than if their upper and lower corners were cut away to form the lateral passages. The bricks I4 are similarly arranged with respect to one another and to the bricks I3, so that vertical fiues I5 are formed and there are lateral passageways through each series (at I2), and at most points throughout the checkerwork, each flue I5`has a latera1 communication with four adjacent ues.

It will be seen vthat if abnormally high pressure flow tends to occur in any iiue, there will be relief thereof in lateral directions to other ues, thus equalizing iiow pressures in the various iiues and producing better uniformity of heat absorption and radiation throughout the checkerwork. Again, if one flue becomes clogged, the gas or air enteringat either end of the flue will be by-passed around the obstruction, through the passageways at I2, thus permitting the major portion of the flue to function `in substantially its normal manner. v

In order to-avoid horizontal shifting of one course of bricks on another, as through thermal expansion or contraction -or slight distortion of the furnace structure, I provide a verticallystepped relation as between the courses in which the bricks I3 are laid and the courses of bricks I4. To this end, the lowermost courses of bricks I4 (as shown in Figs. 1 and 4) are of one or two inches less height than the remaining bricks I4 in each column, so that each succeeding brick the bricks I3, forming the top course, are similarly vertically shortened in order that their top surfaces will be in the same horizontal plane as the top surfaces of the bricks I4.

In Fig. 5, I show a brick I8 that can be uti-.

lized in the same manner as the bricks I3 and I4, to form the checkerwork. In this case however, recesses I'I in the vertical edges of the bricks are inclined so that the streams of gas and air can flow therethrough more smoothly and with a reduction of eddy currents tending to result from the impingement of the gas stream on the upper and lower walls of these passageways, in either direction of cw. Also, the sloping surfaces reduce the danger of clust collecting in and clogging these passageways. The dust not only tends to slide oil the llower surfaces of the passageways, but down-flowing gases will tend to blow the dust of! more readily than if these surfaces were horizontal.

Fig. 6 shows another modified form of brick that can be used instead of the bricks of Figs. 1 to 5. In this case, each brick I8 has median ribs that are cut away or recessed at 20, to provide the lateral passageways. The smooth, straight vertical ends of each brick abut against the ribs I9, when the bricks are assembled as are the bricks in Figs. 1 to 3. v

I claim as my invention:

1. checkerwork forfurnaces, comprising vertical flues formed of bricks in superposed relation and each having vertical ribs in abutting relation with ribs of vertically-adjacent bricks, and certain bricks having their vertical edges in abutting engagement with vertical sides of horizontally-adjacent bricks, the said edges having horizontally-extending depressions formed therein, to provide lateral passageways between the ues, the depressions each being symmetrically dis- 4 -f f posed with respect to the horizontal median plane of its brick, and each being of materially less vertical Width than theedge of its brick and having its upper and lower walls so inclined as to have the passagewavs slope from each flue to another ue.

2. Checkerwork for furnaces, comprising vertical flues formed of bricks in superposed rela\ tion and each having vertical ribs in abutting relation with ribs of vertically-adjacent bricks, and certain bricks having their vertical edges in abutting engagement with vertical sides of horizontally-adjacent bricks, the said edges having horizontally-extending depressions formed therein, to provide lateralv passageways between the ues, the upper and lower walls of the depressions being so inclined as to have the passageways slope from each flue to other ues.

3. Checkerwork for furnaces, comprising vertical ues formed of bricks in superposed relation,

with certain bricks having their vertical edges in abutting engagement with vertical sides of adjacent bricks, there being lateral passageways formed through the bricks of the checkerwork and the upper and lower walls of the passageways being so inclined as to have the passage- Ways slope from each ue to other ilues.

JAMES E. MACDONALD.

REFERENCES CITED The following references are of record in the lle of this patent:

UNITED STATES PATENTS 

